Install Building Wall Sheathing

Wall sheathing is an exterior wall covering that adds structural strength and serves as a vapor barrier. It is positioned between the siding or veneer and the framing of a wall. Sheathing can be made of a layer wood-based panel, foil-covered foam panel, house wrap or a combination of these. The combination of materials, or sheathing system, is determined by the common weather conditions at the construction site.

Proprietary sheathing systems use other materials and can come as 2- by 4-foot panels. There are specific manufacturer's instructions that come with these sheathing systems and must be adhered to. This will ensure the best sheathing protection and uphold the warranty.

Even on a clear day, atmospheric moisture vapor will penetrate the exterior of a home to some degree, including siding and brick veneer. Siding and veneer prevent water droplet penetration. Wall sheathing prevents water vapor and droplet penetration into the interior of the building. Wall sheathing is the second line of defense, behind siding or veneers.

Instructions

Getting started

1. Determine the recommended sheathing system for the home's location.

There are commonly used standard sheathing materials available as well as special proprietary sheathing systems.

Always check local building codes. This will avoid the failure of a building inspection and having to do the job over again.

2. Determine the sheathing configuration. Some homes require wood-based sheathing on the surface of all exterior walls, followed by house-wrap sheathing. This configuration is covered here by these steps.

Others require wood panels only on corners with foam sheathing between the corner wood sheathing followed by house-wrap sheathing.

House wrap is generally recommended when using any wood-based sheathing.

3. Prepare the framing for sheathing installation.

Remove all remaining unnecessary nails, screws, boards, etc. from the exterior of the framing. This will ensure that the sheathing will sit flat against the framing when fastened.

4. Install the portions of flashing that must be positioned "behind" the sheathing around doors, windows and other features that protrude through the walls--generally, the tops of doors and windows. Flashing techniques are recommended by door and window manufacturers individually and will specify flashing to be installed before and after sheathing and house wrap installation.

Flashing is a skill that always considers the flow of water droplets in relation to the various locations on a building. There are many items that can protrude through exterior walls as a design of the building. Always use manufacturer-recommended flashing techniques, order of flashing installation relative to sheathing and required flashing types.

5. Cut a standard 4- by 8-foot chipboard or plywood panel to be used for basic sheathing to fit vertically at the corner of a wall. The height of walls may require a portion to be removed from the end. Other wall heights may require additional sheathing pieces above the first full-sized panel.

Measure and cut out for windows, doors or other openings in the wall.

Use the appropriate tools to cut the measurements.

Basically, any straight line can be cut using a circular saw. Curved cuts can be made using a reciprocating saw or jigsaw. A drill can be used to start a hole for the jigsaw if needed.

The vertical edge opposite of the corner must be centered on the framing member, usually a 2x4 stud. The 4-foot width of the first panel usually does not need to be cut. Be sure to start on a corner where the vertical framing members allow for a 4-foot centering to occur on the panel's edge opposite the corner when possible.

All edges of a panel must fall on a framing member. Sides usually fall on a vertical framing member.

6. Nail the sheathing panel in place.

Hold the sheathing panel in place. Place 6d common nails at the perimeter of the panel 6 inches apart and one nail in each corner. For the framing members inside the perimeter, place nails 8 to 12 inches apart. Sheathing must be nailed to all framing members under the sheathing panel.

Follow steps five and six until all exterior wall surfaces are covered with wood-based sheathing.

7. Install house-wrap sheathing.

Starting at the bottom of an exterior wall, spread and fasten house-wrap material to the wood-based sheathing, usually with staples. All upper wraps must overlap the lower. Make sure there are no holes and no places for water to drop behind any house wrap.

House-wrap tape must be applied in key places. Always follow the manufacturer's recommendations.

8. Install the portions of flashing around doors, windows and other features that protrude through the wall where flashing must be wrapped "over" the sheathing and house wrap. This is the inverse of step four and generally covers flashing at the sides and bottom of doors and windows. Sometimes, flashing already installed at these locations is bent outward until sheathing and wrap has been installed. Then it is bent against the wall and fastened.

Follow the flashing techniques recommended by individual manufactures of doors, windows, vents, etc. These will detail flashing installed after sheathing and house wrap installation.

Corner beads

Friday, March 21, 2014